This invention generally relates to a device for determining the number and types of vehicles passing through an automated car wash system. More specifically, this invention relates to a device and method for determining the number and types of vehicles passing through an automated car wash using ultrasonic sensors that determine the height of different portions of each vehicle.
Current automated car washes typically include dryer bags that provide a flow of air over the vehicle surface as the vehicle approaches the exit of the car wash. A variety of dryer bag arrangements are known. Some arrangements include controllers that position the dryer bags at a preselected distance from the surface of the vehicle to ensure sufficient drying. Such controllers typically include sensors mounted on the end of the bag that detect the presence of the surface of the vehicle as the vehicle moves through the drying stage of the automated car wash.
While such conventional systems are useful, they are not without shortcomings and drawbacks. For example, such systems do not distinguish between vehicle types and, therefore, cannot provide any special dryer position control that may be desirable under certain circumstances. For example, when an open bed pick-up truck is moving through the automated car wash, it is often possible that the open bed contains mud or other substances when the vehicle is approaching the drying stage in the car wash. With conventional sensors, a dryer bag typically is positioned very close to the horizontal surface of the open truck bed. This introduces the likelihood that the dryer bag will become dirty as the mud or other substances are blown about within the truck bed. Further, the mud or other substances may contaminate the sensors positioned on the bag, which results in faulty operation of the bag position controller as subsequent vehicles pass through the drying stage of the car wash.
Therefore, it is desirable to provide a system that controls the position of a dryer within an automated car wash based upon a recognition of the type of vehicle that is currently entering the dryer stage of the car wash. This invention addresses that need by providing a system where sensors are positioned above the pathway of the vehicle that facilitate recognizing the type of vehicle. Vehicle type recognition systems have been proposed in the past. An example of such a system is shown in U.S. Pat. No. 5,173,692. That system includes ultrasonic sensors that measure the heights of various portions of a vehicle, which information is used to determine the number and type of vehicles passing beneath the sensors. Prior to this invention, however, no one has suggested using a vehicle type recognition system for controlling an automated car wash as will be described below.